In an existing In-Cell touch display panel, a common electrode layer for a display function is generally divided into a plurality of common electrode blocks, which are electrically connected with a controlling Integrated Circuit (IC) via the respective wirings. The common electrode blocks are also operable as (i.e. reused as) touch electrodes, that is, in a display state, the common electrode blocks are configured to receive a common voltage signal, while in a touch sensing state, the common electrode blocks operate as touch driving electrodes for receiving touch driving signals.
Typically, the wirings connected with the common electrode blocks couple with other wirings of the touch display panel, thus generating therebetween parasitic capacitances, which increase as the length of the wirings increases. Therefore, the wirings corresponding to the common electrode blocks in proximity to the controlling IC cause relatively small parasitic capacitances, while the wirings corresponding to the common electrode blocks away from the controlling IC cause relatively large parasitic capacitances. Such differences of the parasitic capacitances result in differences between the desired preset time for touch sensing by the various common electrode blocks. However, the preset time for the touch sensing by the common electrode blocks is identical in the related art, so that the accuracy of the touch sensing by the various common electrode blocks is significantly decreased.